function mostrar(div1, div2)
{
                        this.document.getElementById(div1).style.visibility='visible'
                        this.document.getElementById(div2).style.visibility='hidden'                      
}
function ocultar(div1, div2)
{
                        this.document.getElementById(div1).style.visibility='hidden'
                        this.document.getElementById(div2).style.visibility='visible'                      
}		
function asignar(idExam)
{                           
      document.homeAlum.examen.value = idExam;
      document.homeAlum.opcion.value = "rendir";                                                                  
}
